In reply to Dave Cundy:
> I also wear an old pair of woolen socks over my wrists when ice climbing. Works a treat as your wrist is where the blood is forced towards the skin. Can't see the point of cycling arm warmers in this context, just more kit to carry with little thickness and insulation value.
> I wished i'd done that when paragliding in winter, back in the 90's. Numb hands when flying and excruciating hot aches after landing.
Dave, the sock thing works for you and (as we can see above) works for others. It's clearly a more flexible option. They will come off and on a bit more easily.
The arm warmers (for me) go on when I know I'll be climbing or ski mountaineering in cold conditions. It would definitely be a mega faff to strip down to base layers when about to start climbing. Mind you, I imagine that carried as an add on layer they'd be about the same bulk as a pair of cut off socks? As such they wouldn't seem to represent additional kit?
All I can say in terms of insulation is that my hands get cold if I don't wear roubaix arm warmers and when the wind blows hard and presses my outer garments against me, my arms also feel colder when I'm not wearing them.
It's all about options and choice from what's available among them.